I've been working on cars a while and this is honestly the first car I haven't been able to fix. Here it is... my own personal 1994 Honda Accord EX (vtec) Auto. 4 door 133K mi... Runs and starts up fine. It's not really a money pit but a time pit I have spent hours and hours on this electrical problem and am on the verge of letting it go despite the plans I had for it being an around town family car for us.

I think the check engine light is grounded but I cant tell where? Basicly the MIL is always on except when the engine is being cranked over. I've pulled codes... many. I've gone through them all.... one was a 22 ELD (under hood fuse box). Replaced that and fixed a bad connector + wiring down there but some of is still "stiff" in the harness in that one harnes. Code is gone, but code 1 O2s is still there and does not go away after replacement. All O2s wiring, vacuum lines and grounds have been gone over countless times according to factory manual and passed tests. One odd wire I unintentionally tested with a LED test light on the back of the ECM had a hot and grounded (red&green) reading simotaneously. I have never seen one of the LED's light up a dim red & green split down the middle at the same time lit. I don't know if that's normal or not maybe somebody can help me get started in the right direction. Overall I really wish I knew why the check engine light is permanantly on because I really think it's a short or another bad ECM. I really don't think the O2s circuit is grounding the light either it checks out according to the manual. Please HELP somebody.. I really need this car and if it's always in open loop, I won't have a lot to do with making it my daily driver due to personal taste.


Modified by 085714accord at 12:02 PM 10/3/2008

 

So to clarify it is throwing a code and isn't just a solid cel?

I reread it but at one point you say it's throwing a code then another you said it's permanently on because of a short or something.

If the CEL is staying on solid, from my experience it was related to a bad ECU.

If it's flashing a O2 sensor code - what unit did you replace it with certain brands tend to act funky in Hondas namely Bosch.

 

the check engine light is on but will flashes the trouble code when the SCS is jumped then it's working fine...and you have a problem also code 22 is not the ELD it's the VTEC pressure switch fault as for code 1 it's the O2 sensor circut it's the white wire on the O2 sensor (OEM) it goes to the wht/red wire on D14 on the ECU are you sure it's a code 1 and not a code 10? have you tried to reset the the ECU as a code 1 will not show up right after a reset until driven where as a code IAT will show up right when the car is started...

 

I got what your saying. I think it's solid because I replaced it once with a new part.... even though it was a BOSCH it should have gone out after the reset. Not only that the MIL stays on just like the original sensor is in place and the car didn't have a MIL before the engine was replaced and it sat for 2 years. It just doesn't seem right... the book explains that this code shows up after road tests and isn't just on.
How can I tell if I have a bad ECM... is there any for sure of knowing by doing a test that you know of? How often do Honda ECM's go out... are they suceptable to damage if one or more of the 2 or 3 wire sensors are crossed and the engine is started? Id like to know that because, I did have some wires to sensors crossed up. Only because the car was such a basket case when i got it from a friend... It had no engine and missing parts, not to mention I didn't take it apart. Thanks for your help so far. I really appreciate it.

 

Please help more... I have questions for you! I don't understand how the ECM would disply a 10? how would it display 0? So I guess it could be that because I don't know how to recognize that code.. could you please tell me how to decifer? Also Yes I reset the ECM after I put the O2s in I disconnected the battery and pulled the fuse.
THIS SHOULD CLARIFY & as you may well know: When you key a Honda on to the "RUN" position the MIL (& D4 light if auto.) does a bulb check and they both should go out at the same time (mine MIL does not!) also you can hear a relay Kick back over at the same time when the lights should go out. Side Note: Does anybody know what relay this is? I'm guessing PGM-Fi relay because the fuel pumps pressurize during this same interval.
HERE IS THE KICKER: My MIL does not go out before the engine is started! This has to mean something! It's like the ECM saying I'm going to be permanantly running OPEN loop before the engine is even started. And as stated it does not ever go out unless the stater motor engaged even then you can see it flashing with each engine pulse.

BTW: I meant I just fixed a code 20 which is the ELD. But a long time ago I did get a 22 out of it again and again (I tested it out OK grn/ylw wire I believe), may have mis-read it from the ECM back then for a 20. Regardless now all it displays is Onw solid flash and that's it now but I still have the problem where the bulb will not go out in the run position before the engine is started. If this is perfectly normal then please tell me it will save me much grief. But it does not make sense for O2s code to do that sisnce it isnt even used by the computer till closed loop. PLEASE Help more if you can. So far I really appreciate your help! Thank You.

 

what? your saying you know what codes it throws, but then you say:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 085714accord &raquo;</TD></TR><TR><TD CLASS="quote">Please help more... I have questions for you! I don't understand how the ECM would disply a 10? how would it display 0?.</TD></TR></TABLE>

short flashes are a single digit, long flshes are a 10 digit.

so one long flash would be a 10.

one long and three short would be a 13.